In this article, I argue that the research field of religion and development and diaconal studies, the study of Christian social practice, share a common subject of inquiry: the social impact of religion. The field of religion and development investigates this mainly with a focus on the Global South and within the discursive framework of the concept of development, while diaconal studies has thus far taken a Christian perspective and a historic focus on the Global North. Recent paradigm shifts in the development discourse (post-development critique, 2030 Agenda for Sustainable Development as a global framework, critique of the secularist approach) put the field of religion and development under pressure to broaden its scope. Moreover, there is no clear lead discipline in the religion and development debate yet, raising questions about its disciplinary location in academic institutions and curricula. The field of diaconal studies is challenged by increasing religious pluralism and under pressure to consider perspectives from the Global South. Impulses from the recent advances in the conceptualisation of ecumenical diaconia as a new paradigm of Christian social service push the field to move beyond its historic focus on assistance and care. The aim of this article is to juxtapose these two fields of academic study and to bring them into mutual dialogue. The article reflects on both fields and their respective advantages and disadvantages and highlights areas of overlap. It goes on to propose a broadened discipline of diaconal studies, reshaped as the Study of Religious Social Practice, as a new academic field. The focus of this field would be the impact of religion on society in global perspective, across religious traditions and geographic contexts.